A case-controlled retrospective study of the causes and implications of moderate to severe leukocytosis in dogs in South Africa

1. Sandra M. Weltan¹, 
2. Andrew L. Leisewitz²,
3. Amelia Goddard³

Article first published online: 2 JUN 2008

DOI: 10.1111/j.1939-165X.2008.00037.x

©2008 American Society for Veterinary Clinical Pathology

Issue

Veterinary Clinical Pathology

Volume 37, Issue 2, pages 164–172, June 2008

Additional Information(Show All)

Keywords:

• Dog;
• hypoalbuminemia;
• lymphocytosis;
• monocytosis;
• neutrophilia;
• thrombocytopenia

Background: Previous studies showed that dogs with extreme leukocytosis had specific types of diseases, long hospitalization times, and high mortality rates.

Objectives: The aim of this study was to determine whether dogs with moderate to severe leukocytosis are likely to have similar results compared with age-matched control dogs.

Methods: Records at the Onderstepoort Veterinary Academic Hospital, University of Pretoria, were examined retrospectively from dogs with ≥35 × 10⁹ WBC/L (Leukocytosis Group) and dogs with ≤30 × 10⁹ WBC/L and ≤0.5 × 10⁹ band neutrophils/L (Control Group). Hematologic and serum protein data, final diagnosis, and effect of glucocorticoid treatment were compared between groups.

Results: One hundred eighty-two dogs were included in the Leukocytosis Group and 179 in the Control Group. Compared with dogs in the Control Group, significantly more dogs in the Leukocytosis Group had infections, babesiosis, immune-mediated hematologic disease, and necrosis. Hospitalization time and neutrophil, lymphocyte, and monocyte counts were significantly higher and HCT, eosinophil count, platelet count, and serum albumin concentration were lower in dogs in the Leukocytosis Group (P<.0001). There was no difference in leukocyte counts between glucocorticoid-treated and non-glucocorticoid-treated dogs. Survival did not differ between Leukocytosis and Control Groups; however, a significant relationship was found between total neutrophil (mature+band) count and survival (P=.01).

Conclusions: Dogs with leukocytosis of ≥35 × 10⁹/L are more likely to have bacterial and fungal infections, complicated babesiosis, immune-mediated hematologic disease, and necrosis. The total neutrophil count has a significant impact on outcome